Piston.



G. H. STALLMAN.

PISTON.

APPLICATION FILED DEO.11, 1911..

Patented July 9, 1912.

GBANVILLE H. STALLMAN, 012 onrcaoo, rumors.

PISTON.

Specification of Letters Patent.

Patented July 9, 1912.

Application filed December 11, 1911. Serial No. 664,985.

To all whom it may concern:

Be it known that I, GRANVILLE H. STALL- MAN, a citizen of the UnitedStates, residing at Chicago, in the con. 5' of Cook and State ofIllinois, have invented certain new and useful Im rovements in Pistons,of which the following is a specification.

This invention relates to improvements in single-acting fluid-actuatedpistons or press-heads of the rodless type, particularly adapted, thoughnot necessarily limited in its use, to compacting plastic material, suchas sausage and the like, and to expel the same from an inclosure throughan outlet opening; and one of the objects of the in- Vention is toprovide an improved piston of this class having packing upon which thepressure fluid directly acts to automatically adjust the same to form afluid-tight joint to prevent the escape of fluid, while at the same timethe packing will be capable of contracting or assuming a position, whenthe pressure is relieved, to permit the piston or press-head to fall orreturn freely in the cylinder without the application of power thereto.

A further object of the invention is to provide an improved piston ofthis class having means to permit the escape of the pressure fluid atdifferent points in the stroke of the piston.

For the attainmentof these ends and the accomplishment of other new anduseful objects, as will appear, the invention consists in the featuresof novelty in the con- I struction, combination and arrangement of theseveral parts generally shown in the accompanying drawing and describedin the specification, but more particularly pointed out in the appendedclaims.

In the drawing, Figure 1 is a sectional elevation of a cylinder having apiston therein constructed in accordance with the principles of thisinvention. Fig. 2. is a sectional plan view taken on the line 22 of Fig.1 and looking in the direction of the arrows. Fig. 3 is a detail view ofgraduated openings in one of the piston members.

The present application is a substitute application coveringsubstantially the same subject-matter as presented in the applicantsapplication for patent for a iston, filed in the United States Patent05cc on or about October 27 1911, having Serial No. 657,154.

Referring more particularlyto the drawing and in the presentexemplitication of the invention the designates generally an inclosurein the form of a cylinder w-ithinwhich the piston operates, and intowhich cylinder the act-uating fluid is admitted adjacent. the basethereof through an inlet pipe 11.

The piston is of sectional structure and embodies spaced members 12 and13, arranged one above the other and of a diameter and configuration tosubstantially fill the cylinder, The member 12 constitutes the head ofthe piston and is preferably reduced in thickness adjacent its peripheryand shaped to form a circumferential flange 14 projecting away from theoperating face of the head, and this flange is provided with an inclinedface 15 along the edge thereof, against which face the packing 16 bears.This packing 16 is of annular construction and is arranged between themembers 12 and 13 with one edge bearing against the inclined face 17 ofthe member 13, and serves tosupport the member 12 and to space the twomembers apart. The members 12 and 13 are each provided with acircumferential recess 18 adjacent their circumferences which open in adirection toward each other, and these grooves or recesses 18 areenlarged'laterally as at 19 adjacent the base of the recess and towardthe periphery of the members 12 and 13. An annular packing ring 20,which is constructed of any suitable elastic material such as leather,rubber or the like, is arranged within the packing 16 and abutting theinner face thereof. The extremities of the packing 20 project into therecesses 18 in the members 12 and 13 and terminate adjacent the enlargedportion 19 of the recess, whereby the members 12 and 13 are spacedapart. r y

In order to hold the packing 20 against displacement, and in order toform a fluid tight joint between one end of the packing 20 and thesection 12 of the piston, an elastic packing ring 21 is provided, whichis seated in the recess 18 ad'acent the extremity of the packing 20 anin proximity to the enlarged portion 19 of the recess. so that when thepacking ring 20 is compressed a portion thereof will be forced into theortion 19 of the recesses 18. Any suita le means may be employed forcompressing the packing 21, and for this purp se a compression ring 22is provided,

reference numeral 10 which has an extending rim 23 of a 'con-'figuration to conform to the configuration 18. This packing r1ng 22 isprovided with any suitable means for compressing the packing material'21, by means of the movement of the ring, such for example, as thebolts 25, which are threaded into the mem ber 12 and.which force the rimof the said packing ring to compress the packing 21. The other end ofthe packing is -com pressed in a similar manner by'meansof a packingring 26 having an extending r'nn 27 with an inclined face which bearsagainst the packing 21 in the recess 18 of the member 13. The packingring 26 is" operatively moved and is held in position in any suitablemanner, such for example, as by means of the bolts 28 which extendthrough the member 13 from the under side thereof and are threaded intothe ring .26 'to secureit in 29 is formed with a reduced portion 30,-

thereby providing a shoulder 31, and at the bottom of the opening 30 isan aperture '32 to permit a bolt 33 to be inserted therethrough. AWasher 34: is provided which abuts the shoulder 31, and the threadedportion of the bolt extending through the aper- 'ture 32 is threadedinto a suitable thread hole 35 in the hub of the member 13. In order toprovide a suitable packing around thebolt 33 the lower end of theopening 30 is provided with inclined faces and a wedgeshaped clampingring 36 is inserted in the opening, between which and the lower inclinedfaces packing material 37 is inserted. A clamping nut 38 formed withhexagonal head 0 reduced size is threaded into the opening 30, and bearsagainst the ring 36 to compress the packing material 37 about the bolt33. The upper edge of the opening 29 is preferably threaded to receive acap plate 39, which prevents the. material contained in the cylinderfrom clogging the opening 29, and permits ready access to the head ofthe bolt 33, whereby it may be adjusted to properly position the members12 and 13 with respect to each other.

In order to insure a tight fit of the packing 16 against the wall of thecylinder, which will be sufiicient to prevent leakage about thecylinder, and in order to render the degreeof pressure of the packingagainst the wall of the cylinder variable,

so'as to allow the piston to drop or return to its normal positionfreely, the member 13 ofthe piston 1s preferably in the form of a spiderto permit the flllld' to pass readily throughout from beneath. and intocontact with the packing- 20. When this fluid pressure is exerted uponthe packing 20'1t, as well as the packing 16 being elastic will forcethe latter tightly against the wall of the cylinder, while at the sametime the pressure of the fluid will be exerted against the member 12 toraise the piston.

To permit the fluid under pressure to escape from the cylinder as thepiston reac es; the limit, or any predetermined point in its operativemovement and to chviate the danger'of the piston being blown out of oragainst the' head of the cylinder by the pressure of the fluid, and topermit the piston to readily return when the supply of fluid through thepipe is cut off, or the pressure becomes reduced, the member 13 isprovided with longitudinal openings 40, which extend through the wallthereof at suitable points and are preferably grad-.

uated and so arranged that they will be 0 ened at different points ofthe stroke of t e piston. This is accomplished by arranging the openings40 longitudinally of the iston and in such positions that the smalleropenings will pass above the to of the cylinder or will open to theatmosp ere in advance of the others, and will thereby gradually reducethe pressure behind the piston by permitting the fluid to escape. Whenthe pressure is thus relieved, the pressure upon the packing 16 and 20is also relieved, and the piston' will drop to as- .sume a position inaccordance with the pressure remaining, or will assume the normalposition, the packing 16 and 20 being permitted to contract slightly soas not to interfere with the return of the piston.

The primary object of the openings 40 is to prevent the piston frombeing forced out of the cylinder and to provide for the release ofpressure when the piston reaches a predetermined point. The aduatedopenmgs are for the purpose 0 allowing for a variation of pressure andvolume of the fluid under pressure. If the smaller openings do notpresent s'uflicient outlet openings, the piston will rise still higherto uncover the other ports and more of the fluid under pressure will beallowed to escape. As soon as the pressure under the piston is reduced,it will fall back within the cylinder, and, if the" pressure ismaintained at a constant value by the escape of fluid from thehorizontal openings 40, the pistonwill assume and be maintained in astationary position.

The surfaces 15 and 17 are m'clmed mwardly toward; each other, thepurpose thereof being to direct the packing 16 outwardly when themembers 12 and 13 are compressed or drawn together by the bolt 33. Aslight compression of the packing 16 occurs when the piston is underpressure by reason of the fact that the member 13 is not exactlybalanced, due to thedif'ference in area above and below the member 13,the top area being less by an amount of equal to the cross-sectionalarea of the packing 16. Under normal working conditions this differenceis only sufiicient to produce a slight compression of the packing 16between the faces 15 and 17 WhlCh results in the application of thepacking to the Wall of the cylinder, due to the inclination of the saidfaces.

The threaded portion of the opening 29 in the member 12 may be utilizedfor the insertion of a tool orv device by means of which the piston maybe lifted out of the cylinder 10 when desired. It is also evident thatthe construction of the member 13 is such as to permit ready access tothe bolts 25 to adjust the position of the clamping ring i 26. The bolts25 are preferably disposed so that they are between the bolts 28, andare therefore between the ribs of the spider where they may be easilyadjusted from the bottom of the piston without separating the means forexpanding the said elastic mempiston members.

With this improved construction it is i manifest that the packing 20 and16 are di- 1 rectly acted upon by the fluid which oper-i ates thepiston, the pressure of which fluid controls the degree of engagement ofthe packing with the wall of the cylinder, therei by dispensing with anymechanical means for expanding the packing.

packing 20 is free from any support or contact with any other supportingelement, whereby the fluid may freely act directly thereupon, with thefurther result that the packing will freely expand to form a tight jointwhen the pressure is exerted upon the iston and will contract when saidpressure is removed to prevent undue friction of the packing with thewalls of the cylinder,

forming a surrounding wall for the spacewith its inner face freelyexposed to the space and means for preventing said members from moving aart beyond a fixed distance, said space aving communication Furthermore,the larger portion of the inner face of the.

freely exposed on one side of the said space, 7

said space having an opening leading through the member on the pressureside of the piston, and an intermediate member for securing one edge ofthe packing -to the piston member.

3. The combination of a cylinder, a piston movable therein and operableb fluid pressure, an expansible packing between the members and 'xtendmgacross the space with its inner face freely exposed to the space, therebeing one or more passages through the member on the pressure side ofthe piston communicating with said space whereby the pressure fluid willact directly upon the packing to force the same outwardly, anintermediate member and means with which said intermediate membercooperates to secure the packing to one of the piston members.

4. A piston embodying two spaced members connected together and providedin their adjacent faces with opposed recesses, elastic packing extendingacross the space between the members and with its edges extending intothe recesses, an elastic member seated in one of the recesses andabutting the adjacent portion of the packing, and

ber for securing the packing to one of the piston members.

5. A piston embodying two spaced members connected together and providedin their adjacent faces with opposed recesses, an elastic packingextending across the space between the members and wit-h its edgesextending into the recess, an elastic member seated in one of therecesses and abutting the adjacent portion of the packing, and means forexpanding the said elastic member for securing the packing to one of thepiston members, the other member being provided with one or morepassages therethrough communicating with the said space.

6. A piston embodying two spaced members connected together and providedin their adjacent faces with opposed recesses, elastic packing extendingacross the space between the members and with its edges extending intothe recesses, an elastic member seated in one of the recesses andabutting the adjacent portion of the packing, an intermediate memberdisposed between the first two members and having a portion projectinginto the recess to engage the elastic member, and means for forcing theintermediate member toward the piston member to compress said elasticmember.

7. 3A piston embodying two spaced members connected together andprovided in their adjacent faces with opposed recesses, elastic packingextending across the space between the members and with its edgesextending into the recesses, an elastic member seated in one of therecesses and abutting the adjacent portion of the packing, an.intermediate member disposed between the first two members and having aportion prospaced from each other, elastic packing between the membersextending across the space, one of the membershaving an openingtherethrough communicating with the space, the other memberhaving arecess into which the edge of the packing projects, said recess havingan offset portion, an elastic member in the recess and abutting thepacking, an intermediate member project.-

ing into the recess, means connecting the members, and means foradjusting the intermediate member -to compress the elastic member toforce a portion of the packing intothe said offset portion of therecess.

9. A piston embodying two members connected together to form a spacetherebetween and provided in adjacent faces with opposed recesses,elastic packing extendingacross the space and freely exposed to thespace, the edges of the packing projecting into the recesses, an elasticmember in one of the recesses abutting the adjacent portion of thepacking, an intermediate member projecting into the recess, and meansfor'adjusting the intermediate member to compress the elastic member.

10. The combination of a cylinder, a fluid actuated piston embodying twomembers connected together to form .a space therebetween andhavingexposed recesses in their adjacent faces, elastic ackirig extendingacross the space and having its edges seated in the recesses, an elasticmember in one of the recesses abutting the adjacent portion seated ineach of the recesses and abutting;

the adjacent portion of the packing, packing rings disposed between thefirst two members and each havinga rim portion exstruction, elasticpacking extending across 7 the space between the members and with itsedges extending intothe recesses, an elastic member seated in each ofthe recesses and abutting the adjacent ortion of the packing, packingrings disposed between the first two members each having rimportionsextending intoone of the'recesses to engage the elastic member,and means adjustably to secure each of the packing rings to theirrespective piston member, the fastening means for one ring beingdisposed between the ribs of the member of spider construction to permiteasyaccess thereto.

13. A piston comprising two spaced members connected together I andprovided in their adjacent faces with opposed recesses, one of saidmembers being of spider construction, elastic packing extending acrossthe space between the members and with its edges extending into therecesses, an elastic member seated in each of the recesses and abuttingthe adjacent portion of the packing, packing r1ngs dlsposed between thefirst two members each having rim portions extending into one of therecesses to engage the elastlc member, and means adjustably to secureeach of the packing rings to their respective iston member, thefastening means forte lower ring extending through the lower pistonmember, and the fastening means for the upper ring being threaded intothe upper member from below and disposed between the ribs of the lowermember.

14. The combination with a cylinder, of a fluid actuated pliston forreceiving pressure on one side t ereof and embodying two members spacedapart, means connecting said members and preventing their separationmore than a predetermined amount and permittin their approximation,elastic packing isposed between the members and freely exposed to thespace, said space also having a free opening through one of the' membersto the pressure side of the piston, and the last named member beingprovided with openings arranged to permit an escapement of the pressurefluid at different points during the stroke of the piston.

15. The combination with a cylinder, of a fluid actuated iston forreceivm pressure on one side t ereof and embo ymg two members spacedapart, means connecting said members and preventing their separa: tionmore than a predetermined amount and permitting their approximation,elastic packing disposed between the members andv freely exposed to thespace, said space also having a free opening through one of the membersto the pressure side of the iston, and the last named member being ormedwith graduated openingsthrough the periphery thereof arranged atdiflerent points along the member to vary the escapement of pressure asthe piston is moved in the cylinder.

16. In a device of the class described, the combination with a cylinder,of a fluid actuated piston for receiving pressure'on one side thereofand embodying two members spaced apart, means connecting said membersand preventing their separation more than a predetermined amount andpermitting their approximation, elastic packing disposed between themembers and freely exposed to the space, said space also having a freeopening through one of the members to the pressure side of the piston,and the last named member being provided with openings in the peripherycommunicating with the interior space, the said openings being arrangedalong the member to form a graduated escapement for fluid pressure fromthe pressure side of the piston when it reaches the top of the cylinder.

17. In a sausage stufiing machine, the combination with a cylinder of arodless piston head movable therein and comprising two members spacedapart, elastic packing disposed between the members at their peripheriesand freely exposed to ressure through one of said members, per orationsbeing provided through the sides of the last named member arranged alongthe member and graduated in size to provide a graduated escapement forfluid pressure from the cylinder.

18. In a sausage stuffing machine, the

combination of a cylinder open at one end, and a rodless piston movabletherein, comprising members spaced apart, elastic packing disposedbetween the members, one of them being apertured at the center andhaving perforations therefrom through the periphery, the saidperforations being graduated in size and arranged along the axis of themember, so that there is a, graduated escapement of pressure from thecylinder as the piston is moved outwardly at the top of the cylinder.

19. In a sausage stufling machine, the combination of a cylinder open atone end, and a rodless piston movable therein, comprising members spacedapart, elastic packing disposed between the members, one of them beingapertured at the center and having perforations therefrom through theperiphery, the said perforations being graduated in size and arrangedalong the axis of the member with the smallestopenings nearest the openend of the cylinder to provide for a gradually increasing escapement offluid pressure from the cylinder as the piston is moved outwardly.

20. A rodless piston head for a sausage stufling machine, comprising twomembers spaced apart, one of them being of spider formation with aperforated rim, elastic packing disposed between the members at "theiredges and freely exposed on the inside thereof, and means to connect themembers to prevent their separation and permit their approximation, thesaid perforations being graduated in size and arranged along the saidmember in an axial direction.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribin witnesses, on this 9th day of December, D.1911.

GRANVILLE H. STALLMAN.

Witnesses:

CHARLES H. SEEM, K. W. WONNELL.

